Fluid control mechanism



Oct. 11, 1938. c. F. slBBE 2,133,118

FLUID CONTROL MECHANISM Filed sept. 27,' 1935 4 sheets-sheet 1 f h M m 1S .w/ w .NN mm M. um n NSS www N O E NH N mm X m E uw 0 J J www m.\\ mm @www Q N u n l. mw m N h Nhv hm \b\DQ\ MS\ l m. NQ mw .mv www Sw m\ w Kvm N Oct. 11, 1938. c. F. slBBE 2,133,118

FLUID CONTROL MECHNISM Filed Sept. 227', 1935 4 Sheets-Sheet 2 Oct. 11, 193s.

C. F.. SIBBE FLUID CONTROL MEcHANIsM Filed Sept. 27, 1935 4 Sheets-511861'I 3 oct. 11, 193s. C, SlBBE 2,133,118

FLUID CONTROL MECHANI'SM Filed sept. 27, 19:55 4 sheets-sheety 4 lll-um nf n Patented oct. 11, 1938 FLUID CONTROL DIECHANISM carl vF. sibbe, Philadelphia, Pa., assigner to American Engineering Company, Philadelphia, Pa., a corporation of Pennsylvania Application September 27, 1935, Serial No. 42,495

11 Claims.

This invention relates to fluid systems, and more particularly to the control mechanisms employed in such systems.

One object of the present invention is to generally improve certain hydraulic control mechanisms of the general type disclosed in United States patent to Earl Cannon No. 1,656,034, and to adapt such devices for use in connection with hydraulic presses and similar apparatus.

Another object is to provide certain improved features to control mechanisms of the above type, which permits operation thereof through a predetermined cycle.

Another object is to provide an improved control for pumps which functions to rst place the pump on working stroke, so that a platen or other apparatus operated thereby will move toward the work, to then reverse the discharge of the pump after a predetermined pressure has been 20 exerted upon the work to cause the platen to move away from said work, and when the platen has reached its upper limit of travel, to cause the purnp to be returned to the neutral position and be retained in this position until a new cycle of operation is desired.

A further Object is to provide adjustable stop means on the hydraulic press associated with the control mechanism to limit the travel thereof in one direction. Y

A further object is to provide novel by-pass means between the pump and the press so constructed as to stop the movement of the platen toward the work at any position betweenY its limits of travel.

A further object is to provide improved mechanical and electrical control devices for stopping the movement of the platen, and for conditioning the control apparatus for a new cycle of operation.

Other and further objects will become apparent as the description of the invention progresses.

Of the drawings: Y

Fig. 1 is a diagrammatic view, partly in section showing my improved control mechanism associated with a hydraulic press.

Fig. 2 is a plan view of the pump and associated control mechanism.

Fig. 3 is an enlarged detail sectional view taken substantially along line 3 3 of Fig. 2.

Fig. 4 is an end view of the mechanism shown in Fig. 3 with certain of the actuating rods removed, looking from right to left thereof.

Fig, 5 is a plan view partly in section of the timer mechanism associated with the pump con- 55 trol.

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Fig. 6 is an end view of the mechanism shown in Fig. 5, showing particularly the indicating mechanism associated therewith.

Fig. 7 is a sectional view taken substantially along line 1 1 of Fig. 5, showing the stop nuts 5 of the timer mechanism separated.

Fig. 8 is a sectional View taken substantially along line 8 3 of Fig. 3.

Fig. 9 is a sectional view taken substantially along line 9 9 of Fig. 3, showing the position of 10 the parts when the toggle passes through its mid` position.

Fig. l0 is a view similar to Fig. 9, but showing the position of the parts when the toggle has been operated to one of its limiting positions.

Fig. 11 is a similar view showing the position of the parts when the toggle has been actuated to another of its limiting positions of adjustment.

Fig. 12 is a diagrammatic detail view showing different positions of the upper end of the toggle and the latch mechanism therefor when the upper arm of the toggle moves in the direction indicated by the arrows.

Fig. 13 is a similar view showing various positions assumed by the upper end of the toggle and the latch therefor when the latter swings in the opposite direction indicated by the arrow.

Fig. 14 is an end view partly in section taken substantially along line I 4 14 of Fig. 12.

Fig. 15 is a diagrammatic view of an alternative construction showing electric operating and control means for certain ofthe elements thereof, and

Fig. 16 is an enlarged detail view partly in section of certain by-pas's valves and the operating means therefor.

Referring to the drawings, the numeral l indicates a fluid system comprising in the present instance a variable stroke reversible discharge pump P, and an hydraulic press I-I. Pump P may be mounted in any suitable' manner upon a bed plate 2, having provided therein a iiuid reser- Voir' 3, and in the present instance is driven by an electric motor also suitably mounted upon said bed plate. Pump P may beconnected to the upper end of a iiuid motor A of the press by means of a pipe 6 and to the lower ends of iuid motors B and B of said press by a Vpipe 1 and branch pipes l and l, respectively. Pump P may be ofthe general type shown and described in United States Patent No. 1,077,979, which includes a stroke control element E (Figs. 3 and 5) whereby the quantity and direction of flow of fluid through the pipes 6 and l may be Varied, the construction being such that when the shiftable element 8 is in the position shown in Fig. 4

fluid is delivered under pressure through the pipe I3 and is drawn into the pump through pipe 1, but when the control element 8 is in the opposite position shown in Fig. 10, fluid is delivered through the pipe 1 and drawn in through the pipe 6. However, when shiftable element 8 is in its intermediate or neutral position there is no flow through either of the pipes 6 or 1. The stroke of the shiftable element 8 may be controlled by the timer mechanism 8, shown more particularly in Figs. 5 and 7. This mechanism comprises a pair of spaced rods II which are secured at their inner ends to the control element 8. The outer ends of these rods rigidly support a crosshead I2 which may be actuated in opposite directions between a pair of spaced stop nuts I3 and I4. These nuts are respectively mounted on oppositely threaded sections I5 and i8 of a shaft I1 which is journaled in a bearing I8 supported by a bracket i9 secured in any suitable manner to the pump casing. When the shaft I1 is turned in one direction, the stop nuts I3 and I4 separate to increase the space between, and consequently the movement of the crosshead I2 and the control element 8. However, when the shaft I1 is turned in the opposite direction the stop nuts I3 and I4 are moved toward each other to decrease the movement of the crosshead I2. When the nuts I3 and i4 nally clamp the crosshead to prevent a further movement thereof, the control element 8 is in the mid or neutral position. Should it be desirable to permit the control element 8 to move in one direction a greater amount than in the other it is only necessary to vary the relative spacing of the stop nuts i3 and i4 with respect to the crosshead I2. Such a change thus permits the pump to deliver a greater volume of fluid to one side of the system than the other, and also affords an accurate neutral setting. The stop nuts I3 and I4 are prevented from turning when the shaft I1 is actuated, as above dcscribed, by means of a guiding rib 2l which extends from an arm 22 of the bracket I9 into a recess 23 of the stop nuts I3 and I4. Arm 22 has one end secured to the pump and the other end to an outer hub portion 24 which is provided with an internally threaded aperture 25 adapted to receive the correspondingly threaded bearing I8. The bearing I8 is thus adjustably mounted. The shaft l1 may be locked against axial movement by means of a pair of collars 23 operatively associated with opposite ends of the bearing I8. The supporting bracket le is provided with an additional arm 21 which extends from the hub portion 24 to the pump. A hand wheel 38 may be mounted on the outer end of operating shaft l1 to eiect operation thereof.

Since it is desirable to know at all times the Speed of the motors A and B, B of the hydraulic press H, an indicator 39 is provided. This indicator comprises a gear wheel 3i having arotatable mounting on a stud 32 supported by the bracket arm 21. A pointer 33 isy rigidly secured to the stud 32 adjacent one face of gear wheel 3|. The latter may be actuated in accordance with a movement of the stop nuts I3 and i4, and hence variations in the stroke of the pump P by means of a pinion 34, which is so mounted on the shaft l1 as to mesh with the gear wheel 3I. The indicator 28 may be calibrated so as to have a zero setting when the control element 8 and the associated parts are in the mid or neutral position.

Mechanism 35 is also provided whereby the stroke contro-lling element 8 may be oppositely actuated from one extreme position through neutral to the other extreme position only when the pressure in the system exceeds a predetermined value. The mechanism 35 is also adapted to counteract the tendency of the stroke controlling element 8 to return from advance position to the neutral or mid position. The mechanism 35 for accomplishing these results comprises a toggle 36 having an upper arm 31 and a lower arm 38, as shown more particularly in Figs. l and 3. The

lower arm 38 comprises a tubular sc ction 38, a

lower end 48 of which is closed and provided with trunnions 4I which are journaled in spaced bearings 42. An upper open end 43 of the tubular section 39 may be closed by a telescoping cap section 44 having trunnions 45 which are journaled in the lower ends 48 of a pair of strap members 41, constituting the upper toggle arm 31. rIhe strap members 41 may be pivotally mounted on a pin 43 which is supported on a section 43 of a bracket 5I secured to the casing of pump P. The portion of the bracket 5I immediately above section 49 is recessed to provide spaced abutments 52 and 53 for a member 54, having trunnions 55 journaled in the adjacent ends of the strap member 41. The spacing of the abutments 52 and 53 corresponds to the maximum movement of the control element 8, which in turn is controlled by the maximum operation of the stop nuts i3 and I4. The member 54 may be resiliently held in engagement with one or the other of the abutments 52 and 53 by means of a spring 58, one end of which abuts against the telescoping casing'44 and the other against the adjustable seat 51 mounted on a threaded screw 58 extending through the lower end 48 of the tubular section 39. Thus the member 54 may be actuated from engagement with one ci the abutments, say 53, into engagement with the other abutment 52, only when the line of action of the spring 56 is su'iciently shifted beyond the dead center line of the toggle.

The toggle, or so called load and re mechanism 36, may be actuated as just described, by means of a pair of fluid motors 59 and 6I, which are respectively connected to the opposite sides of the iiuid power system represented by the pipes 6 and 1, the pump P and the motors A and B, B of the hydraulic press. These motors comprise cylinders 62 and 63 constituting portions of the bracket 5I, and a pair of inter-connected plungers 64 and 65, respectively. A member 66 is rigidly secured to a central portion of the plungers 64 and 65 and is provided with trunnions 61 which are journaled in the strap sections 46 that constitute the upper toggle arm 31. Leakage around plungers 64 and 65 may be prevented by packing 68 and a pair of glands 69 and 1I, which are respectively clamped to the cylinders 62 and 63 by a pair of tie rods 12 and nuts 13, as shown particularly in Figs. l and 4.

Since the movement of the member 54 between the abutments 52 and 53 corresponds to the maximum movement of the stroke controlling element 8, I provide mechanism 14, Figs. 3, 4, 9, 10 and 11, inclusive, which permits variations in the movement of the element 8 by the timer 9 independently of the spring-loaded toggle mechanism 36. The mechanism 14 comprises a rod 15 which supports the member 54 and extends through aligned apertures in the abutments 52 and 53. These apertures are suiciently large to receive a pair of sleeves 16 and 11, respectively. The sleeves respectively abut against opposite sides of the member 54 and nuts 18 on the ends of the Vrod 15. Hence when the member 54 is actuated by the toggle mechanism 36, the rod 'I5 and the sleeves I6 and I'I are correspondingly moved.

A pair of crossheads 'I9 and 8| are apertured to receive slidably the sleeves 'I6 and 11, respectively, and may be forced into engagement with the nuts 'I8 on the ends of the rod 'I5 by means oI a pair of springs 82 and 83. The springs 82 and 83 encircle rods 84 and 85 which extend from a pair of guide rods 86 and 8'| slidably mounted in the pump P, respectively. The guide rods 86 and 81 are connected to the stroke-controlling element 8. The rods 84 and 85 pass through apertures in the opposite ends of the inner crosshead 8| and are provided with shoulders 88 and 89 against which said crosshead may be actuated by the force of the springs 83 and 82. The outer crosshead 'I9 is similarly apertured to receive the ends of the j rods 84 and 85 which respectively terminate in shoulders 9| and 92 formed by adjusting nuts 93 and 94.

Considering the operation of the toggle mechanism 36, when the member 54 is moved from the intermediate position shown in Fig. 9l to that in Fig. 11 under the action of said toggle mechanism, the mechanism 'I4 is moved bodily until the crosshead |2 engages the stop nut I4 of the timer mechanism 9. Should the stop nut I4 be so positioned that the crosshead I2 engages the same before the toggle-operated member 54 engages the abutment 53, the movement of said member 54 is not interferred with, inasmuch as the springs 82 and 83 collapse to permit the continued movement of the inner crosshead 8| and the rod 15. The iinal position of these parts is illustrated in Fig. 11. The force of the springs 82 and 83 is such that they not only counteract the normal tendency of the control element 8 to move to its mid-position, but also prevent a relative movement .between the crosshead 'I9 and the spring supporting rods 84 and 85, until the control element 8 has moved the desired extent as defined by the position of the stop nut I4.

When the toggle mechanism 36 is actuated from the advanced position above described, through the neutral position of Fig. 9, the line of action of the spring 56 is changed, so that the member 54 is snapped into engagement with the Opposite abutment 52. The position of the parts is now as shown in Fig. 10. Here again the nut I3 is so positioned by the timer mechanism 9 that the control element 8 cannot be moved the maximum distance from its mid-position, as defined by the space between the abutment 52 and the adjacent side of the member 54 when the latter is in the position shown in Fig. 9. The line of action of the spring 56 being now in the opposite direction, the member 54 is positively held in engagement with the abutment 52 until a further operation of the toggle mechanism 36. The pump P is thus reversed for each movement of the toggle mechanism 36.

Considering the operation of the control mechanism thus far described, it is seen that when the driving motor 4 is energized, and the shiftable control element 8 is maintained in its neutral position by the timer mechanism 9, the pump P fails to discharge through either of the pipes 6 and 1. However, when this timer mechanism 9 is operated to separate the stop nuts I3 and I4 the shiftable element 8 is actuated under the force of the springs 82 and 83 until the crosshead |2 engages one or the other of the stop nuts I3, I4, depending upon which abutment the toggle actuated member 54 it is in engagement with. Assuming the parts to be in the position shown in Fig. .11, i

the force of the spring 56 until the line of action' of the latter changes, whereupon the toggle mechanism 36, and the control element 8 are snapped into the position shown in Fig. 10. Thus the stroke control element 8 is positively actuated from its advance position in one direction to its advance position in the other direction, and the platen correspondingly reversed only when the pressure in the uid system reaches the predetermined value at which reversal is to occur. Moreover, pump P is held on stroke independent of its tendency to return to its no-stroke or midposition. Should it be found desirable to cause the pressure in one side. of the system, say in the pipe 6, to reach a higher value than that on the other side of the system before the pump P is reversed, the plunger 65 may be made smaller than the plunger 64, as shown in Fig. 3. The control mechanism thus far described is fully disclosed in the patent to Earl Cannon, hereinbefore reerred to.

The present invention contemplates certain improvements and additions to this mechanism, as well as to the hydraulic press H, and to the control circuits between the pump and the press, which will now be described in detail.

Referring more particularly to Figs. 1 to 4, it will be seen that the upper ends of levers 3l of the toggle mechanism 36 extend above bracket 5|, and have provided therein a pin |66. Pin |88'is adapted to engage the lower surface of a pair of spaced levers lill pivotally supported at one end thereof, as shown at |62, to an extension |93 of bracket 5|. Levers |6| are integrally connected by spaced cross members |64 and |05, respectively. Extension |93 is provided with a horizontal projection |86 overlying the pivotedy end of levers lili. A set screw |87 is mounted near the outer end of projection |86 which engages an adjustable spring seat |88, and a spring |69 extends between said spring seat and the cross member |65. Thus, when spring |89 is placed under compression it urges levers I! downwardly against pin |86. Levers IBI are provided withy a pair of transversely aligned notches H0, which receive pin |98 when the toggle 36 is in its neutral or vertically aligned position, as shown in fullv lines in Fig. 3.

Pivotally supported on pins III and extending inwardly from the inner sides of levers IIII,

K is a depending plate ||2 having extensions ||3 provided at the opposite ends thereof. When the upper end of the toggle moves in the direction of the arrows shown in Fig. 13, pin |80 will engage plate ||2 and cause the extensions ||3 thereon to close the open end of notches ||0 and thereby permit the toggle mechanism to complete its movement in the reverse direction, as hereinbefore described. As pin |08 clears plate I2 the latter will move to its normal vertical position byk 'y gravity. If desired, a spring may be employed to assure the return of said plate to normal position when released by pin |88.

racket 5| has pivotally mounted at I I4 near the upper right hand end thereof (Fig. 3) a cam H5 which is adapted to engage Vthe under side of cross member |84, and thereby swing levers I 0| upwardly to release pin from notches H0. Also pivotally mounted at H6 to bracket 5| and disposed beneath cam H5, is a lever I I1 which is adapted to engage an ear 41 (Fig. 4) extending laterally from one of the strap members 41, to urge the lower end of the toggle to the left (Fig. 3) simultaneously with the operation of the latch levers |0| by cam H5. Integral with cam H5 and lever H1 are actuating arms H0 and H9 respectively, which are pivotally connected at the free ends thereof to a vertically disposed link 20. The lower end of link |20 is pivoted to one end of a lever |2| pivotally mounted intermediate its ends at |22 to a supporting bracket |23. The other end of lever |2| has pivotally connected thereto the upper end of a link |24 to the lower end of which is pivotally connected the free end of an arm |25, also pivotally supported on bracket |23. Arm |25 has integral therewith a laterally extending foot treadle |26 disposed adjacent the hydraulic press H. A spring |21 is secured to and extends between foot treadle |26 and the laterally extending projection 20' of bracket |23. Thus, upon the release of treadle |26 after a depression thereof, spring |21 will restore the latter, as Well as cam H and lever H1, to normal position.

It therefore is clear that in order to condition the apparatus for a cycle of operation it is only necessary for the operator to depress foot treadle |26, thereby causing the toggle 36 to be operated by its spring 56 to the position shown in Fig. 1 1 and the right hand position indicated by the broken lines in Fig. 18. The pump will then deliver fluid pressure to motor A, causing the platen connected thereto to descend toward the work. When the platen reaches the work a pressure is developed in the system which is transmitted to the toggle by means of motor 6|. When this pressure is suiicientv to overcome the pressure exerted by spring 56, the toggle will actuate the pump control 8 in the reverse direction as hereinbefore described, causing the pump to deliver fluid pressure to motors B and B', which return the platen to normal position. As the pin |00 moves toward a central position it will engage plate l2 causing the extensions H3 thereon to close the open end of notches H0, thereby permitting pin |00 to move to the extreme left hand position shown in broken lines in Figs. l2 and 13. When the platen reaches its upper limit of travel, pressure again will build up in the system, causing motor 59 to swing the toggle toward neutral position, and when pin |06 registers with notches H0, spring |06 will urge levers |0| downwardly to lock the toggle in this position. The apparatus is now conditioned for a new cycle of operation.

In the event it is desired to have the platen reciprocate without coming to rest at the end of each cycle of operation a spring-urged latch |30 is provided. Thus when the treadle is moved downwardly to its fullest extent of movement latch |30 will engage the end thereof to hold the parts in operated position. Cam H5 will thereby hold levers |0| out of engagement with pin |00. When moved to operated position the lower end of lever H1 will have cleared the upper end of ear 41 so as not to interfere with the operation of the toggle. The device will now continue to reverse in the manner set forth in the patent to Earl Cannon, previously referred to.

The hydraulic press H comprises a supporting standard |3| having a material-supporting table |32 mounted at the upper end thereof. The upper stationary member |33 of the press H upon which motor A is mounted, is supported in spaced relation with table |32, by means of rods |34 provided at the corners thereof. These rods are each provided with shoulders |35 and |36 near the upper and lower ends thereof, which respectively engage `the under side of member |33 and the top surface of table |32. The reduced portions |31 and |38, respectively, of these rods extend through member |33 and table |32, and nuts |30 rigidly secure the parts in position. The upper surface of the press platen |40 is engaged by the piston rod I4! of fuid motor A, while the lower surface thereof is in engagement with the piston rods |42 and |43 of motors B and B. Platen |40 is guided in its vertical movement by the rods |34. Motor A is secured in any suitable manner to member |33, while motors B and B' are secured to the under side of table |32, as shown in Fig. l. Thus, when motor A is subjected to fluid pressure platen |40 will be moved downwardly toward the work, and when a reversal of the fluid in the system is effected, as previously described, motors B and B operate to return the platen to normal position.

In order to adapt the press for operation upon materials of different sizes, or to enable maximum speed of operation of the press, the travel of the platen must be subject to control. To this end a pair of simultaneously operable, adjustable stops |44 and |45' is provided. These stops are secured to the lower ends of a pair of screw shafts |46 and |41, which extend upwardly through apertures |46 and |49 provided in member |33. Shafts |46 and |41 are actuated by a pair of interconnected, internally threaded bevel gears |50 and |5|, supported upon the upper surface of member |33 and held against vertical displacement by guide brackets |52 and |53, respectively, secured to said member |33. Bevel gears |50 and |5| mesh respectively, with a pair of vertically disposed bevel gears |54 and |55, secured to the opposite ends of a shaft |56 mounted for rotation in bearing bracketsk |51, |51, secured to and extending upwardlyrfrom member |33. A handle Wheel |58 secured to shaft |56 and disposed between bearing brackets |51 may be employed to rotate bevel gears |54 and |55 which through bevel gears |50 and |5| effect a simultaneous vertical displacement of shafts |46 and |41', and consequently of stops |44 and |45. Thus, when platen |40 engages these stops the pressure in the system will build up, causing motor 59 to actuate the toggle to a neutral position where it will be held in place by the latch levers |0| as previously described. In certain types of work, such, for example, as die setting, it is desirable to have the platen move toward the work as slowly as possible, so that before effecting an operation thereon proper adjustment of all of the parts is assured. To this end a pair of by-pass valves |60 and |6| is provided in pipes 6 and 1 respectively. The upper and lower ports |62 and |63 of valves |60 and |6|, respectively, are connected by means of a by-pass pipe |64. As shown more particularly in Fig. 1, valve |60 is provided with an inlet port |66 and an outlet port |61. Valve |60 has also provided therein a pair o f interconnected valve elements |68 and |60, which are adapted to engage valve seats and 1| respectively. Fig. l shows the parts in normal position wherein valve element |68 is in seated position, thereby preventing the passage of iiuid from pipe 6 to pipe 1, while valve |69 is unseated to permit fluid to pass therethrough to motor A, or from motor A back to pump P, depending upon the adjustment of the latter.

Valve |6| is of similar construction, and also has provided therein a pair of interconnected valve elements |12 and |13 which are adapted respectively, to engage valve seats |14 and |15. When the apparatus is in normal position valve element |12 is in seated position and thus prevents the passage of fluid from pipe 1 to pipe 6, while valve |13 is unseated so that uid passing through pipe 1 will either flow toward or from motors B and B', through its ports |16 and |11, depending upon the adjustment of pump P.

The valve stems |18 and |19 of valves |68 and 6| extend through 'suitable packing provided in the casings thereof. The lower end of valve stem |18 has secured thereto a laterally extending pin |88 which engages into a longitudinally extending slot |8| provided at the right hand end of a lever |82 pivoted intermediate its ends on an arm |83 of a bracket |84, secured to pipe 6. 'Ihe left hand end of lever |82 is provided with a laterally extending pin |85 which engages into a slot |86 provided at the right hand end of a second lever |81. Lever |81 is also pivoted intermediate itsends at |88 to another arm |89 of bracket |84.

The upper end of valve stem |19 has also secured thereto a laterally extending pin |98 which engages into a longitudinally extending slot |9| provided at the right hand end of a lever |92 pvotally mounted on the upper end of a bracket |93 secured to pipe 1. These levers are connected for simultaneous operation by means of a lever |94 pivoted intermediate its ends at |95 to the lower end of bracket |93 and a pair of links |96 and |91, as shown in Fig. 1. The extreme left hand end of lever |81 has secured thereto a chain or other mechanism |98, which, as shown in Fig. 1, may be positioned adjacent the hydraulic press I-I. It therefore is seen that when it is desired to hold platen |48 in any position of adjustment during the downward travel thereof, it is only necessary to pull downwardly on chain |98. This motion is transmitted to the valves through the link and lever mechanism just described, causing seating of valve elements |69 and |13, and unseating of valve elements |18 and |12. Whenthis occurs, fluid passing through pipe 6 will by-pass through valve |88, bly-pass pipe E69, valve |6|, pipe 1, and thence to pump P. It also is clear that the fluid in motors A, B and B', and the fluid in the portions of pipes 6 and 1 disposed to the right (Fig. 1) of valves |68 and |61, will be trapped, thereby forming a hydraulic lock which holds platen |48 against further downward movement. Upon release of chain |98 a spring |99 connected at one end to the left hand end of lever |82 and at the other end to the lower, laterally projecting portion of arm |83 will restore the parts to normal and fluid will again ow to motor A and be evacuated from motors B and B by the action of pump P. By simply manipulating valves 88 and |8| in this manner any desired degrees of adjustment of platen |48 may be effected.

It sometimes is desirable to effect operation of the pump controls and by-pass valves by electrical means. To this end the following mechanism has been provided.

' Referring more particularly to Fig. 15, it is seen that the lower end of link |28 passes through a solenoid 288 supported in any suitable manner upon the bracket |23. A wire 28| connects the upper end of solenoid 208 to a switch position,

88' which in turn operates the stroke adjusting means of pump P, causing the latter to. deliver fluid pressure to pipe 6 and suction to pipe 1', as previously described. If it is desired to effect repeated reversals of platen |48' the switch 282 is maintained in closed position. Solenoid 288 will then hold cam ||5 and lever ||1 in operated position. Upon deenergization of solenoid 288 by opening switch 282 a spring 281 disposed between the top of said solenoid, and an abutment 288 at the lower end of link |28 will restore the parts to operative position, and the pump P will consequently be held on neutral when the platen assumes a normal position.

Referring to Figs. l5 and 16, electric means has also been provided to actuate the by-pass valves |68 and |6|', mounted respectively in pipes 6 and 1' to control the movement of platen |48. The construction of these valves is similar to that of valves |68 and |6| shown in Fig. 1, and accordingly, a detailed description thereof is unnecessary. Valve |88' has provided therein a pair of interconnected valve elements |88' and |69', adapted respectively to seat upon valve seats |18' and |1I'. Valve |6| has also provided therein a pair of interconnected valve elements |12 and |13 adapted to seat upon valve seats |14' and When the parts are in normal position, as shown in Fig. 16, fluid is prevented from flowing through the by-pass pipe |64'.

The valve stems |18' and |19' have respectively secured to the free ends thereof, extensions 2|8 and 2H, which form the cores of solenoids 2|2 and 2|3. These solenoids are mounted on brackets 2I4 and 2|5, secured respectively to pipes 6' and 1'.

Valve element |88' is normally held upon its seat |18 by a spring 2|6 extending between solenoid 212 and a shoulder 2 I1 provided near the top of extension 218. Valve element |12' is likewise normally held 'upon its seat |14' by a spring 2|8 extending between solenoid 2|3 and a shoulder 2|9 provided at the lower end of extension 2| A switch 228 controls the operation of solenoids 2|2 and 2|3, and has one pole thereof connected to bus bar 288 by a wire 22|. A second wire 222 connects the other pole of switch 228 with the lower end of solenoid 2|3, a third wire 223 connects the upper end of said solenoid with the upper end of solenoid 2|2, while a fourth wire 224 connects the lower end of solenoid 2|2 with bus bar 284. The solenoids are thus connected for simultaneous operationA and when switch 228 is closed valve elements |69 and |13 will be urged upon their respective seats, thereby causing the iluid from pump P to by-passthrough pipe |84', as previously described. When this occurs platen |48 will be held against further movement. Upon deenergization of the solenoids springs 218 and 2| 8 will restore the parts to normal position, and the operation of platen |48 will be resumed.

While the embodiments herein described are admirably adapted to fulll the objects primarily stated, it is to be understood that it is not intended to limit the invention thereto since it may be embodied in other forms, all coming within the scope of the claims which follow.

What is claimed is:

l. In a uid system, the combination with a reversible discharge pump, having a pair of pipes leading therefrom, of means for controlling the flow of iuid through said pipes, comprising a stroke control element operatively connected to said pump, a spring loaded toggle operative on said element, pressure responsive means operative on said toggle to condition the same for operation in either direction under predetermined conditions, latch means adapted to retain said toggle and stroke control element in neutral position, means for releasing said latch, additional means for urging said toggle in one direction upon the release of said latch, means for rendering said latch means ineffective when said toggle swings past neutral position in the opposite direction, and common actuating means for said releasing means and additional means.

2. In a fluid system, the combination with a reversible discharge pump, of a stroke adjusting element for said pump, means responsive to the pressure changes in said system for controlling the operation of said pump, said means including a spring loaded toggle operatively associated with said stroke controlling element, latch means for retaining said toggle in neutral position, means mounted on said latch for rendering the latter ineffective when the toggle moves 1n one direction, said last mentioned means being ineffective when the toggle swings in the reverse direction whereby the latter is held against movement when it assumes a neutral position, means for releasing said latch, and means for urging said toggle in the said reverse direction upon release of said latch.

3. In a fluid system, the combination with a reversible discharge pump, of a stroke adjusting element for said pump, load and fire mechanism operatively connected to said element, said load and re mechanism When moved in one direction from a neutral position conditioning said pump for discharge in one direction, and when moved in the reverse direction from neutral said load and fire mechanism conditions said pump for discharge in the reverse direction, latch means for retaining said load and re mechanism in neutral position, means for releasing said latch, means for urging said load and fire mechanism in one direction upon release of said latch, and means provided on said latch means for rendering the latter ineffective when said load and fire mechanism moves in the reverse direction.

4. In a fluid system, the combination with a reversible discharge pump, of stroke control means for said pump, load and fire mechanism operatively connected to said means and movable to different positions of adjustment to Control the flow of fluid in said system, latch means for retaining said load and iire mechanism in neutral position, means for releasing said latch, means for urging said load and fire mechanism in one direction upon release of said latch, and means for rendering said latch means ineffective when said load and iire mechanism moves in the reverse direction, and rendering said latch means effective when said load and iire mechanism moves in said one direction whereby said load and re mechanism will be held against movement when reaching its neutral position of adjustment.

5. In a fluid system, the combination with a reversible discharge pump, of a stroke adjusting element for said pump, load and iire mechanism operatively connected to said element, said load and fire mechanism when moved in one direction from a neutral position conditioning said pump for discharge in one direction, and When moved in the reverse direction from neutral said load and fire mechanism conditions said pump for discharge in the reverse direction, latch means cooperative with said load and fire mechanism for retaining the latter in neutral position, means for releasing said latch, means for urging said load and fire mechanism in one direction upon release of said latch, and means provided on said latch means and engageable by said load and fire mechanism to render said latch means ineffective when said load and iire mechanism moves -in the reverse direction.

6. In a fluid system, the combination with a reversible discharge pump, of a stroke adjusting element for said pump, load and fire mechanism operatively connected to said elementfsaid load and iire mechanism when moved in one direction from a neutral position conditioning said pump for discharge in one direction, and when moved in the reverse direction from neutral said load and re mechanism conditions said pump for discharge in the reverse direction, latch means cooperative with said load and iire mechanism to retain the latter in neutral position, means for releasing said latch, actuating means for urging said load and fire mechanism in one direction upon release of said latch, said latch means comprising a pivotal lever having a notch provided therein for receiving a pin on said load and iire mechanism, a pivotal plate mounted adjacent said notch and adapted to be engaged by said pin, when said load and fire mechanism moves in the reverse direction from which it was urged by said actuating means, to close said notch and thereby permit said load and re mechanism to complete its movement in said reverse direction to effect a reversal in the discharge of the pump, said plate moving to inoperative position when released by said pin, means for moving said load and fire mechanism in said one direction toward neutral position, and means for urging said lever into engagement with said pin.

7. In a device of the class described, the combination with a reversible discharge pump, of a control mechanism for said pump including a stroke adjusting element for said pump, a load and fire mechanism operatively connected to said element, latch means normally retaining said load and fire mechanism in neutral position, means for releasing said latch means and causing movement of said load and fire mechanism in one direction to place the pump on stroke, automatic means for actuating said load and fire mechanism in the reverse direction, means for rendering said latch means ineffective when said load and re mechanism moves past neutral position in said reverse direction to effect a reversal in the discharge of said pump, a second automatic means for actuating said load and lire mechanism to neutral position, and means for urging said latch means into engagement with said load and fire means to retain the latter in neutral position.

8. In a device of the class described, the combination with a reversible discharge pump, of a control mechanism for said pump including a stroke adjusting element for said pump, a load and fire mechanism operatively connected to said element, latch means normally retaining said load and re mechanism in neutral position, means for releasing said latch means and causing movement of said load and fire mechanism in one direction to place the pump on stroke, automatic means for actuating said load and fire mechanism in the reverse direction, means for rendering said latch means ineiTective when said load and re mechanism moves past neutral position in said reverse direction to effect a reversal in the discharge of said pump, a second automatic means for actuating said load and re mechanism to neutral position, means for urging said latch means into engagement with said load and fire means to retain the latter in neutral position, and means for varying the time between successive operations of said load and iire mechanism.

9. In a fluid system, the combination with a reversible discharge pump, of a stroke adjusting element for said pump, means for actuating said element in one direction to condition said pump for discharge in one direction, means for actuating said last mentioned means in the reverse direction to condition said pump for discharge in the reverse direction, and means compelling a predetermined cycle of operation of said stroke adjusting element, said last mentioned means comprising a latch adapted to retain said element in neutral position, means for releasing said latch, means for urging said actuating means in one direction upon release o-f said latch, means provided on said latch for rendering the latter ineiective upon operation of Said last vmentioned means in the reverse direction, said last mentioned means being so constructed that when said actuating means returns to neutral position said latch becomes eiective to retain said actuating means and element in said position.

10. In a iluid system, the combination with a reversible discharge pump, of a stroke adjusting element for said pump, load and re mechanism operatively connected to said stroke adjusting element, means operated by the pressure developed by said pump for positioning said load and re mechanism to effect reverse operations of said stroke adjusting element, and means compelling a predetermined cycle of operation vof said stroke adjusting element, said last mentioned means comprising a latch adapted to retain said element in neutral position, means for releasing said latch, means for actuating said load and re mechanism in one direction upon release of said latch, means provided on said latch for rendering the latter ineffective upon operation of said load and re mechanism in the reverse direction, said last mentioned means being so constructed that when said load and fire mechanism returns to neutral position said latch becomes effective to retain said load and re mechanism and element in said position.

11. In a fluid system, the combination with al reversible discharge pump, of a stroke adjusting element for said pump, load and re mechanism operatively connected to said stroke adjusting element, means operated by the pressure developed by said pump for positioning said load and fire mechanism to effect reverse operations of said stroke adjusting element, means compelling a predetermined cycle of operation of said stroke adjusting element, said last mentioned means comprising a latch adapted to retain said element in neutral position, means for releasing said latch, means for actuating said load and nre mechanism in one direction upon release of said latch, means provided on said latch for rendering the latter ineffective upon operation of said load and fire mechanism in the reverse direction, said last mentioned means being so constructed that when said load and re mechanism returns to neutral position said latch becomes effective to retain said load and fire mechanism and element in said position, and means for holding said latch releasing means in latch releasing position whereby continued reversals of said pump may be effected.

CARL F. SIBBE. 

